Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (WCDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks. High Speed Uplink Packet Access (HSUPA) is a data service offered on the uplink of UMTS networks.
A wireless communication network may include a number of access point that can support communication for a number of mobile devices, such as, for example, mobile stations (STA), laptops, cell phones, PDAs, tablets, or similar terminal devices. A STA may communicate with an access point via the downlink (DL) and uplink (UL). The DL (or forward link) refers to the communication link from the access point to the STA, and the UL (or reverse link) refers to the communication link from the STA to the access point.
Mobile stations may move between coverage areas of different wireless networks. For example, a mobile station may often be in an area covered by its Home Public Land Mobile Network (H-PLMN), and occasionally be in a different coverage area served by a Visited Public Land Mobile Network (V-PLMN) that is controlled by a different operator. Also, mobile stations may be equipped to use different radio access technologies (RATs) via different interfaces, for example, Wireless Local Area Network (WLAN) as defined by IEEE 802.11 standards, or 3GPP. Because of increasing inter-network and inter-RAT complexities, network selection and radio interface selection by a mobile station may involve conflicting rule sets and sub-optimal solutions, for which more optimal solutions are desirable.